1. Field of the Invention
The invention relates to double deck connector assemblies, and particularly to an improvement to the connector assembly disclosed in copending application Ser. No. 09/619,864 filed on Jul. 20, 2000.
2. The Related Art
The copending application having the same inventorship and the same title filed on Jul. 20, 2000, generally discloses a double-deck SO DIMM (Small Outline Dual Inline Memory Module) connector assembly where two-step withdrawal of the lower module (daughter card) is achieved for more organizational arrangement. As mentioned in this copending application, each of most existing prior art double-deck connector assemblies is characterized with a relatively larger-dimensioned offset between the upper housing and the lower housing in the front-to-back direction, thus occupying more space on the printed circuit (mother) board on which the connector assembly is seated. Differently, the aforementioned copending application discloses a connector assembly with a relatively smaller-dimensioned offset between the upper and the lower housing in the front-to-back direction for saving the space on the printed circuit (mother) board.
Anyhow, some operators/technicians working on the assembling sometimes prefer to have a one-step withdrawal of the lower module rather than two-step one which is one of the features of the aforementioned copending application in which the lower module may be temporarily retained between the upper deck and the lower deck during rotative withdrawal.
Therefore, an object of the invention is to provide a double-deck connector assembly which owns the advantageous smaller offset as shown in the copending application while permitting one-step withdrawal of the lower module instead.
According to an aspect of the invention, a double-deck connector assembly includes a unitary housing defining upper and lower connection ports with upper and lower central slots for respectively receiving the corresponding upper and lower modules therein. The upper connection port is slightly forwardly offset from the lower connection port. A pair of latch arms extend from two opposite ends of each connection port for retaining the corresponding module in position. A latching lug is formed on each latch arm for locking the module in position wherein the latching lug of the lower latch arm includes a vertical section received within the notch of the lower module and a horizontal section, which is integrally connected to the vertical section, abutting against and positioned on the upper surface of the lower module around the periphery of the corresponding notch, while the latching lug of the upper latch arm includes a vertical section received within the corresponding notch of the upper module and a horizontal section, which is integrally connected to the vertical section, abutting against and positioned on the upper surface of the upper module around the side edge close to said notch. Therefore, the lower module is allowed to be inserted into the lower connection port with the initial angular insertion position which is substantially above the latching lug of the upper latch arm under the condition that the upper connection port is only slightly forwardly offset from the lower connection port. The dimension, position and contour of the latching lug of the upper latch arm are properly configured to correlate the (standard) notch of the lower module for allowing insertion/withdrawal of the lower module with regard to the connector housing via deflection of the upper latch arm.
Specifically, such withdrawal of the lower module is arranged to be done via one step instead of the so-called two steps disclosed in the aforementioned copending application, wherein a guidance face is provided around the upper latch arm for guidably allowing the lower module to continuously/successively upwardly move, after manually releasing the lower latch arm, by capably/automatically deflecting the corresponding upper latch arm away instead of being temporarily held between the upper latch arm and the lower latch arm, so as to meet the user""s desire while still keeping the advantageous smaller offset of the first generation invention disclosed in the aforementioned copending application.